Origin

From early Flemish or Low Germandaler, from German T(h)aler, short for Joachimsthaler, a coin from the silver mine of Joachimsthal ( 'Joachim's valley'), now Jáchymov in the Czech Republic. The term was later applied to a coin used in the Spanish American colonies, which was also widely used in the British North American colonies at the time of the American Revolution, hence adopted as the name of the US monetary unit in the late 18th century.